1. Field of the Invention
The present invention relates to novel compounds having antagonism against corticotropin-releasing factor (hereunder, “CRF”) receptor, salts thereof and medical use of the same.
2. Related Background of the Invention
CRF is a neuropeptide consisting of 41 amino acids which is produced and secreted in the hypothalamus and promotes release of adrenocorticotropic hormone (ACTH) under stress, and it also functions in the brain as a neurotransmitter or neuromodulator, integrating electrophysiology, autonomic nerves and behavior in response to stress.
CRF receptors are of two subtypes, CRF1 receptors and CRF2 receptors, of which CRF1 receptors have been reported to be widely distributed in the cerebral cortex, cerebellum, olfactory bulb, pituitary gland, amygdaloid nucleus and elsewhere.
Numerous low molecular compounds having CRF receptor antagonism have been noted as potential therapeutic agents for a number of diseases including depression, anxiety and stress-related disorders. (See Non-patent document 1)
Disclosed compounds having CRF receptor antagonism include 2,6-dimethoxy-4-methoxymethylphenyl-containing compounds (see Patent document 1), but compounds having a pyrazolo[5,1-b]thiazole skeleton according to the present invention have been neither disclosed nor suggested.
The compound shown below has been disclosed as a compound having a pyrazolo[5,1-b]thiazole skeleton, but its use is for colorimetry. (See Example 16 of Patent document 2)
    [Patent document 1] U.S. Patent Application Publication No. 2004/0224974    [Patent document 2] U.S. Pat. No. 5,234,818    [Non-patent document 1] Drugs of the Future, 24:1089-1098 (1999)